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HA ED JV/CEE'S SCIENCE-GOSSIP. 



matter, and the skeletons were buried by order of the 

 late squire in the churchyard. Some rude beads, 

 apparently of glass, were found in or near the graves, 

 and were preserved, and these were submitted to a 

 learned friend of mine : he pronounced them Danish, 

 but of no special interest. The largest of the 

 skeletons was enclosed in a rude stone grave, not, how- 

 ever, a carefully constructed stone coffin, although 

 a stone had been hollowed for the head and 

 another for the feet. If the beads were Danish, it is 

 natural to assume accordingly, that the bodies were 

 probably those of Danes, and a curious question 

 would be whether the Danes buried their dead in 

 the fashion described. Of course the length of the 

 skeletons is startling. 



The present population of Lundy is small, and 

 though fluctuating a good deal, rarely exceeds fifty ; 

 most are connected with the extensive farm, com- 

 prising nearly all the cultivated land of the island, 

 others belong to the lighthouse service, and a few to 

 the squire's family. Accommodation for visitors is 

 scarce, and the squire does not wish his little kingdom 

 to be frequented by strangers. In summer a fast 

 steamer crosses most weeks from Ilfracombe, and 

 stops for a few hours. Difficult indeed would it be 

 to find a spot so cut off from the great world, and so 

 interesting in its way and yet so difficult of access. 

 When I returned to Instow, I used to feel that I 

 was in the bustle of modern life, though the first time 

 I crossed to Lundy, just after a journey to New York 

 and Birmingham, Instow, at which I was kept twelve 

 days, looked like the ultima thule of England. Since 

 I ceased to reside there, seven and a half years ago, 

 I have not set foot upon it, and the difficulty and 

 uncertainty as to getting to and leaving Lundy, 

 sufficiently explain my long absence from it, although 

 my interest in it is unabated. 

 Wimborne. 



GOSSIP ON CURRENT TOPICS. 

 By W. Mattieu Williams, F.R.A.S., F.C.S. 



MAGNESIUM FLASH PHOTOGRAPHY.— 

 This process, divested of unnecessary com- 

 plexity, consists in obtaining artificial light by simply 

 sprinkling some magnesium dust on gun-cotton, laid on 

 a plate which may be placed on the top of the camera 

 or other suitable position, and when the proper 

 moment arrives the gun-cotton is fired by a match and 

 the negative picture is obtained at once, provided the 

 arrangements are properly carried out. I have lately 

 witnessed its application by an amateur photographer 

 with excellent results, under conditions otherwise 

 hopeless. No glass pavilion is necessary, nor specially 

 painted background. A picture may be taken in any 

 room, and very good effects obtained, provided some 

 artistic taste is employed in the sitting and grouping 

 in reference to furniture and ornaments. 



The flame being large, the shadows are not hard, as 

 when an electric light or magnesium wire is used, and 

 they may be still further softened by judicious use of 

 the gas or lamplight in ordinary use. To obtain this 

 softening effect the cap should be removed a little 

 before flashing. This gives what I may call an 

 under ghost, or gaslight picture not visible as an 

 actual picture, but supplying an appreciable effect in 

 softening the outlines. Amateurs may now take 

 home pictures after business hours, at any time in the 

 evening. This is likely to extend very largely the 

 recreative use of the beautiful art. 



Another advantage of the flash light is that in 

 portraiture the eye is shown at its best. A strong 

 light contracts the iris, but this contraction is by no 

 means instantaneous. Therefore the flashed photo- 

 graph represents the eye as it was in the subdued 

 light or even darkness preceding the flash. The 

 sitter may be startled by the flash, but the picture is 

 not thereby disturbed, as the nervous impulse only 

 travels at the rate of about So to ioo feet per second, 

 and thus "the twinkling of an eye" is a work of 

 time, a slow process compared with instantaneous 

 photography ; the picture is taken before the twink- 

 ling has started. 



An old Experiment. — In a lecture delivered in 

 April last at the Royal Institution, Sir William R. 

 Grove described an experiment he made in 1856, 

 which is suggestive of further research with the 

 modern appliances of more sensitive plates. He cut 

 letters out of paper and placed them between two 

 polished squares of glass with tin foil on the outsides. 

 The tin foil was then electrised like a Leyden jar, for 

 a few seconds, the glasses separated, the letters blown 

 off, and the inside of one of the glasses covered with 

 photographic collodion. This was then exposed to 

 diffused daylight, and on being immersed in the 

 nitrate of silver bath, the part which had been 

 covered with the paper came out dark, the remainder 

 of the plate being unaffected. 



Here we have an effect usually described as photo- 

 graphic in which light is not the artist. Some sort of 

 action is communicated to the silver salt by the 

 electric charge, and it appears to be the same as that 

 communicated by light, but what the nature of that 

 action may be, is at present an absolute mystery, 

 in spite of the imaginary molecular gyrations, 

 oscillations, mean free paths, &c. &c, by which the 

 scientific dreamer conceals his ignorance. If tlie 

 philosophic modesty with which Sir William Grove 

 has treated these mysteries, from the time of his first 

 publication of ' The Correlation of Physical Forces ' 

 in 1842 to the present time, were more general, the 

 prospects of solving them by experimental investiga- 

 tion would be greater. 



Crystal-Making. — When a youngster, I amused 

 myself by making saturated solutions of alum in hot 

 water, placing cinders, &c, in these, and setting 



